This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. The overall goal of this proposal is to identify the underlying genetic causes of MS. Specifically, the current investigation seeks to assess genetic factors related to early-onset Multiple Sclerosis (MS). A vast body of previous research conclusively shows that there is a strong genetic influence on MS. Genes in their germline configuration influence susceptibility, disease progression and most likely, also response to treatment. Despite this evidence, it has been difficult to identify the specific genes involved. Previous work has looked at known genes thought to be candidates for having influence on MS - for example, genes that control immune system function and resistance to viral infection - but this approach has met with partial success. The technology now exists to identify the genes that cause MS susceptibility using unbiased and efficient methods. Identification of the exact molecular basis of MS susceptibility will undoubtedly result in new opportunities for treatment and/or prevention of this cruel disease.